Electro-optical systems are used in a variety of applications such as imaging, targeting, ranging, tracking, surveillance, and reconnaissance, among other military applications. In many systems, imaging sensors sharing a common image plane produce mutually aligned images of a target or “scene.” Mutual alignment of the images ensures accurate alignment of the system components. In particular, various multi-spectral electro-optical systems employ imaging sensors that are receptive to light of different spectral bands, such as infrared thermal imagers and visible color television cameras. Accordingly, multi-spectral electro-optical systems permit an operator to detect and identify target characteristics otherwise concealed in optical systems responsive to light of a single spectral band. Conventionally, boresight misalignments in optical systems have been detected and cured with the use of targeting boards after an initial alignment during manufacture. The alignment tends to drift over time, leading to the need to use targeting boards to periodically adjust the alignment. In such conventional systems, the targeting board is located at a distance from the optical system and illuminated so that it is clearly visible in all sensors. By aligning the sensors with the common targeting board, misalignments in the optical system may be detected and properly addressed.